Method of refining hydrocarbon oil with a sludge-forming reagent



P 16, 1947- v. L. CHECHOT 2,427,589

METHOD OF REFINING HYDROCARBON OIL WITH A SLUDGE-FORMING REAGENT FiledDec. 28, 1945 a z Reag enii OiZ Heailed Drum Saraper ll-zz Coiled Sludge10 v Treaied Oil Fiy. 2

I T-reaied Oil Hates; INVENTOR. G 6)) Kzldimir L. Chev/wt 8* a M Z MOMAN-T 5 Hitorneg/ Patented Sept. 16, 1947 METHOD OF REFINING ROCARBONOIL WITH A SLUDGE-FORMING REAGENT Vladimir L. Chechot, Philadelphia,Pa., assignor to The Atlantic Refining Company, PhiladeL- phia, Pa., acorporation of Pennsylvania Application December 28, 1945, Serial No.637,612

12 Claims.

The present invention relates to the refining of hydrocarbon oil,particularly lubricating oil, by treatment with a sludge-forming reagentat elevated temperature. This invention is especially adapted to thetreatment of lubricating oil stocks with sulfuric acid or other reagentnormally producing a sludge which will not settle readily and which isdifficult to remove from the treated oil.

In accordance with the present invention, hydrocarbon oil is intimatelymixed with a suitable quantity of a sludge-forming refining reagent, andthe mixture is supplied, preferably in the form of a film, to aninclined stationary surface or to a rotating cylindrical surface heatedto a temperature sufiicient to coke or carbonize the sludge resultingfrom the reaction of the sludge-forming reagent with the oil butinsufiicient to deleteriously affect the oil. The rate of supply of themixture as well as the rate of rotation of the cylindrical surface iscontrolled so as to effect deposition and coking of the sludge upon suchsurface, while the treated oil is drained therefrom and separatelycollected. The coked sludge is either continuously or periodicallyremoved from the heated surface by scraping or other means in such amanner as not to contaminate the treated oil.

A variety of hydrocarbon oils may be treated, and include cruderesiduu'ms or bottoms from the distillation of crude petroleum;lubricating oil distillate stocks; parafiinic or naphthenic oilfractions produced by the selective solvent extraction of lubricatingoil distillates or reduced crudes; viscous hydrocarbon oils resultingfrom the destructive or non-destructive hydrogena tion of crude oil orfractions thereof; and tars or tar distillates obtained in the crackingof petroleum for the production of motor fuel.

The refining agents which may be employed in the process of the presentinvention are sludgeforming substances such as concentrated sulfuricacid; 98% sulfuric acid; oleum or fuming sulfuric acid; chlorsulfonicacid; phosphoric acid; alkyl sulfates and acid sulfates such as monoanddinnethyl sulfate, and monoand diethyl sulfate; and active metal halidessuch as aluminum chloride, tin tetrachloride, zinc chloride, ferricchloride, titanium tetrachloride, and

the like. The quantity of refining agent employed varies considerably,depending upon the nature of the oil to be treated and. the activity ofthe agent. Sulfuric acid in amounts of from 1% to 50% by volume of theoil may be used,

2 while active metal halides are satisfactory in quantities of the orderof 0.5% to 10%.

The temperature necessary to coke or carbonize the sludge resulting fromthe reaction of the reagent with the oil varies with the reagentemployed depending upon the activity thereof,

and the character of the sludge. In general, a temperature between 250F. and 600 F. may be used. With concentrated or 66 B. sulfuric acid, atemperature between 400 F. and 600 F. is preferred, althoughtemperatures as low as 250 F. may be used provided the coking time isextended.

The method of the present invention may be carried out either batch-wiseor continuously, the latter mode being preferred. In batch-wiseoperation, for example, a lubricating oil stock such as a reduced crudehaving a Saybolt Universal viscosity of 160 seconds at 210 F., isintimately mixed with a suitable quantity of refining agent, such as1.0% by volume of 66 B. sulfuric acid, and the mixture is supplied tothe upper end of a stationary iron plate inclined at an angle of aboutto the horizontal and electrically heated to a temperature of about 500F. As the oil-acid mixture descends over the plate in the form of afilm, the reaction between the oil and the acid is completed, theresulting acid sludge depositing 0n the heated plate and coking orcarbonizing thereon, while the treated oil substantially free of sludgeflows downthe plate and is drained from the lower edge thereof into asuitable receptacle. The rate of flow of the oil-acid mixture isregulated so that all of the sludge is deposited upon the plate by thetime the treated oil reaches the lower edge of the plate. At such timeas the deposit of coked sludge upon the plate becomes appreciable, forexample, inch in thickness, the supply of oil-acid mixture is shut offand the coked sludge is removed from the plate by scraping with a bladeor wire brush. After the plate has been cleaned, the oil treatingoperation may be resumed. From the above operation there was obtained ayield of 88% by volume of decolorized, sludge-free, substantiallyneutral oil, and slightly less than 12% of dry, porous coked sludge.

My invention may be further illustrated with reference to theaccompanying drawing, in which Figures 1 and 2 representdiagrammatically oil treating systems suitable for carrying out myprocess.

Referring to Figure 1, a hydrocarbon oil stock and a suitable quantityof sludge-forming reagent, such as concentrated sulfuric acid, iscontinuously introduced into mixing vessel I by means of pipes 2 and 3,respectively. The oil and acid is thoroughly mixed in vessel I by meansof stirrer 4, and the mixture of oil and acid, including some acidsludge, is withdrawn from the vessel by valve-controlled pipe 5 anddelivered to a perforated pipe or manifold 6, which functions todistribute the mixture along the length of a heated drum or cylinder Irotating clockwise on the hollow axle 8. The drum 1 may be electricallyheated by means of internal resistance heaters,

or may be heated by circulation of a hot gas or liquid supplied throughthe perforated hollow axle 8. Since the actual method of heating is ofno concern in the present invention, the inclusion of heater details isomitted. Suffice to say that the surface of the drum I is maintained ata temperature between 250 F. and 600 F., and preferably about 500 F.when the refining treatment involves the use of concentrated sulfuricacid. The mixture of oil and acid, with incidental sludge, is spread asa film over the surface of the drum immediately under the distributingmanifold 6, and the reaction between the oil and the acid is completedupon the heated surface of the drum. The acid sludge is deposited on thesurface of the drum and undergoes coking or carbonization. As the drumrotates clockwise, the treated oil substantially free of coked sludgeflows downwardly counterclockwise over the drum and drains from thelowest point thereof into the collecting vessel 9, from which it may beremoved by means of valve-controlled pipe It as desired. The rate offeed of oil-acid mixture to the surface of the drum and the rate ofrotation of the drum is controlled so that little or no oil is carriedin a clockwise direction to contaminate the coked sludge on the upperright quadrant of the drum, and at the same time the acid sludge iscompletely coked and does not drain off with the treated oil. The cokedsludge deposited on the surface of the drum is continuously removedtherefrom by contact with a scraper or blade I I extending lengthwise ofand in close proximity to the surface of the drum. The coked sludge thusdislodged is collected in the hopper I2 from which it may be removed anddisposed of as desired. The coked sludge is usually obtained in the formof a powdery, friable scale which may be used for fuel or otherpurposes. The treated oil removed from vessel 9 is substantially sludgefree and neutral, most of the sulfuric acid initially associated withthe oil being removed therefrom in the form of sludge or sulfur dioxide.The treated oil, by virtue of the acid treatment, is partiallydecolorized, and may be finished by conventional methods such as clayfiltration, dewaxing, etc.

In Figure 2 of the drawing, there is shown a modification of theapparatus employed in Figure 1. In Figure 2, the mixture of oil andsludgeforming reagent, such as sulfuri acid, is supplied to the rightupper quadrant of drum 8 and fiows clockwise in the direction ofrotation of the drum. The treated oil, fr'ee of coked sludge, drainsfrom the lower-most portion of the drum and is collected in vessel 9,while the coked sludge is scraped from the drum by means oflongitudinally disposed blade I I. Here again the rate of supply of theoil-acid mixture to the surface of the drum and the rate of rotation ofthe drum are controlled to give complete deposition and coking of thesludge without entrainment of sludge in the treated oil or entrainmentof treated oil in the coked sludge removed by the scraper II.

While the present invention has been described particularly withreference to the use of sulfuric acid as the treating agent, it isobvious that other sludge-forming reagents may be used in lieu thereof,with consequent adjustments of temperature, rate of flow, etc. When themixture of oil and sludge-forming reagent supplied to the drum 8 or 8 istoo viscous to flow by gravity from the mixing vessel I or I to theperforated distributing manifold 6 or 6' and thence to the surface ofthe drum, a pump may be installed in series with valved-controlled pipe5 or 5 to deliver the oil-reagent mixture at the proper rate of flow,such pump being of the type customarily employed in handling viscous,corrosive materials.

I claim:

1. The method of refining hydrocarbon oil, which comprises intimatelymixing said oil with a sludge-forming reagent, supplying said mixtureinthe form of a film to an inclined surface heated" to a temperaturesuficient to coke the sludge resulting from the reaction of thesludgeforming reagent with the-oil butinsufficient to deleteriouslyaffect the oil, depositing and coking the'sludge upon said heatedsurface, and separately removing said coked sludge and the treated oilfrom said surface.

2. The method of refining hydrocarbon oil, which comprisesintimatelymixing said oil with a sludge-forming-reagent,supplying saidmixture in the form of a film to a rotating surface heated to atemperature sufficient to coke the sludge resulting-from the reaction ofthe sludge-forming reagent' withthe oil but insufiicient todeleteriously affect the oil, depositing and coking the sludge uponsaid' heated rotating surface. and separately-removing said coked sludgeand the treated-oil from said surface.

3. The method of refining hydrocarbon oil, which comprises intimatelymixing said oil with a sludge-forming reagent, supplying said mixture inthe form of a film to a rotating surface heated to a temperaturesufiicient to coke the sludge'resulting from the reaction of thesludgeforming reagent with the oil but insufficient to deleteriouslyaffect the oil, controlling the rate of supply of said mixture-and therate of rotation of said surface "to causedeposition and coking of thesludge upon said surface, and separately removing said: coked sludge andthe treated oil from said surface.

4; The'method of refining hydrocarbon oil, which comprises inti iatelymixing said oil with a sludge-forming reagent-supplying said mixture inthe form of a film to a rotating cylindrical surface heated to atemperature sufficient to coke the sludge resulting'from the reaction ofthe sludge forming reagent with the oil but insufficient todeleteriously affect the oil, controlling the rate of supply of 'saidmixture and the rate of rotation of saidsurface to cause deposition andcoking of substantially all of the sludge upon said surface, drainingthe treated oil substantially free of sludge from said surface, andseparately removingsaid coked sludge from' said surface.

5. The method of refining hydrocarbon oil, which comprises intimatelymixing said oil with sulfuric acid, supplying said mixture in the formof a film'toan inclined surface heated to a temperature sufficient tocoke the sludge resulting from the reaction of sulfuric acid with theoil but insufficient to deleteriously affect the oil, depositing andcoking-the sludge upon said heated surface, and separately removing saidcoked sludge and the treated oil from said surface.

6. The method of refining hydrocarbon oil, which comprises intimatelymixing said oil with sulfuric acid, supplying said mixture in the formof a film to a rotating surface heated to a temperature sufiicient tocoke the sludge resulting from the reaction of the sulfuric acid withthe oil but insufiicient to deleteriously affect the oil, depositing andcoking the sludge upon said heated rotating surface, and separatelyremoving said coked sludge and the treated oil from said surface.

7. The method of refining hydrocarbon oil, which comprises intimatelymixing said oil with sulfuric acid, supplying said mixture in the formof a film to a rotating surface heated to a temperature sufiicient tocoke the sludge resulting from the reaction of the sulfuric acid withthe oil but insufficient to deleteriously affect the oil, controllingthe rate of supply of said mixture and the rate of rotation of saidsurface to cause deposition and coking of the sludge upon said surface,and separately removing said coked sludge and the treated oil from saidsurface.

8. The method of refining hydrocarbon oil, which comprises intimatelymixing said oil with sulfuric acid, supplying said mixture in the formof a film to a rotating cylindrical surface heated to a temperaturesufiicient to coke the sludge resulting from the reaction of thesulfuric acid with the oil but insuificient to deleteriously affect theoil, controlling the rate of supply of said mixture and the rate ofrotation of said surface to cause deposition and coking of substantiallyall of the sludge upon said surface, draining the treated oilsubstantially free of sludge from said surface, and separately removingsaid coked sludge from said surface.

9. The method of refining hydrocarbon oil, which comprises mixing saidoil with sulfuric acid, supplying said mixturein the form of a film toan inclined surface heated to a temperature between 250 F. and 600 F.,depositing and coking the resulting acid sludge upon said heatedsurface, and separately removing said coked acid sludge and the treatedoil from said surface.

10. The method of refining hydrocarbon oil, which comprises mixing saidoil with sulfuric acid, supplying said mixture in the form of a film toa rotating surface heated to a temperature between 250 F. and 600 F.,depositing and coking the resulting acid sludge upon said heatedsurface, and separately removing said coked acid sludge and the treatedoil from said surface.

11. The method of refining hydrocarbon oil, which comprises mixing saidoil with sulfuric acid, supplying said mixture in the form of a film toa rotating surface heated to a temperature between 250 F. and 600 F.,controlling the rate of supply of said mixture and the rate of rotationof said surface to cause deposition and coking of the resulting acidsludge upon said heated surface, and separately removing said coked acidsludge and the treated oil from said surface.

12. The method of refining hydrocarbon oil, which comprises mixin saidoil with sulfuric acid, supplying said mixture in the form of a film toa rotating cylindrical surface heated to a temperature between 250 F.and 600 F., controlling the rate of supply of said mixture and the rateof rotation of said surface to cause deposition and coking ofsubstantially all of the acid sludge upon said heated surface, drainingthe treated oil substantially free of sludge from said surface, andseparately removing said coked sludge from said surface.

VLADIMIR L. CHECHOT.

REFERENCE S CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

